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.TH GROUP_MEMBER 3 2021-03-22 "GNU" "Linux Programmer's Manual"
.SH NAME
group_member \- test whether a process is in a group
.SH SYNOPSIS
.nf
.B #include <unistd.h>
.PP
.BI "int group_member(gid_t " gid );
.fi
.PP
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.PP
.BR group_member ():
.nf
    _GNU_SOURCE
.fi
.SH DESCRIPTION
The
.BR group_member ()
function tests whether any of the caller's supplementary group IDs
(as returned by
.BR getgroups (2))
matches
.IR gid .
.SH RETURN VALUE
The
.BR group_member ()
function returns nonzero if any of the caller's
supplementary group IDs matches
.IR gid ,
and zero otherwise.
.SH CONFORMING TO
This function is a nonstandard GNU extension.
.SH SEE ALSO
.BR getgid (2),
.BR getgroups (2),
.BR getgrouplist (3),
.BR group (5)
.SH COLOPHON
This page is part of release 5.13 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%https://www.kernel.org/doc/man\-pages/.
